Don't build with INSPIRCD_DEBUG=3, it prevents m_spanningtree from being loaded

Unable to load m_spanningtree.so: /home/dev-irc/.local/modules/m_spanningtree.so: undefined symbol: _ZN11CommandSave14SavedTimestampE

.github/workflows/test-devel_release.yml

@@ -41,7 +41,7 @@ jobs:
         cd $GITHUB_WORKSPACE/inspircd/
         patch src/inspircd.cpp < $GITHUB_WORKSPACE/inspircd_mainloop.patch
         ./configure --prefix=$HOME/.local/inspircd --development
-        make -j 4 INSPIRCD_DEBUG=3
+        make -j 4
         make install
     - name: Test with pytest
       run: PYTEST_ARGS='--junit-xml pytest.xml' PATH=~/.local/inspircd/bin:$PATH make